The following table exhibits the breaking-weight of various kinds of wood as given by the authors therein named: Experiments on the Strength of Woods.

KIND OF WOOD.

Length In Feet.

Brdlh. in Inches

Depth in Inches.

Deflection In

Inches at the time of fracture.

Weight in Pounds that broke the piece.

Authorities.

English Oak, young tree

2

1

1

187

482

Tredgold.

Oak, old ship-timber . . .

2.5

1

1

1.5

264

"

,, from old tree ....

2

1

1

138

218

"

., medium quality . .

2.5

1

1

284

Ebbels.

Green Oak........

2.5

1

1

219

"

oak from Riga. . . . . . .

2

1

1

1.25

357

Tredgold.

Green Oak...

1175

8.5

85

3.2

25S12

Butfon.

Beech, medium quality .

2.5

1

1

271

Ebbels.

Alder...

2.5

1

1

212

"

Plane-tree..

2.5

1

1

243

"

Sycamore...

2.5

1

1

214

"

Green Chestnut....

2.5

1

1

180

"

Ash, from young tree . .

25

1

1

2.5

324

Tredgold.

Ash............

25

1

1

2.38

314

"

Common Elm...

25

1

1

216

Ebbels.

Green Witch-Elm ....

2.5

1

1

192

"

" Acacia...

2.5

1

1

249

"

Sp. Mahogany, seasoned .

25

1

1

170

Tredgold.

Hond. „ „

2.5

1

1

255

"

Green Walnut......

2.5

1

1

195

Ebbels.

Lombardy Poplar ....

2.5

1

1

131

"

Abele Poplar....

2.5

1

1

1.5

228

Tredgold.

Teak ..........

7

2

2

4.0

820

Barlow.

Willow....

2.5

1

1

3.0

146

Tredgold.

Birch....

2.5

1

1

207

Ebbels.

Cedar of Libanus, dry . .

2.5

1

1

2.75

165

Tredgold.

Riga Fir....

2.5

1

1

1.3

212

"

Memel Fir........

2.5

1

1

115

218

"

Norway Fir. fr. Long Sd.

2

1

1

1.125

396

"

Mar-Forest Fir....

7

2

2

5.5

360

Barlow.

Scotch Fir, Engl, growth

25

1

1

175

233

Tredgold.

" " ....

2.5

1

1

157

Ebbels.

Christiania white Deal . .

2

1

1

0 937

343

Tredgold.

American white Spruce .

2

1

1

1.312

285

"

Spruce-fir, British growth

2.5

1

1

186

Ebbels.

American Pine. Weymouth

2

1

1

1125

329

Tredgold.

Larch, choice specimen .

2.5

1

1

30

253

"

" medium quality .

2.5

1

1

223

"

„ very young wood .

2.5

1

1

1.75

129

"

Riga Fir..........

4

3

3

4530

Fincham.

Red Pine.........

4

3

3

3780

"

Yellow Pine....

4

3

3

2756

"

Cowrie....

4

3

3

4110

"

Poona....

4

3

3

3990

"

It has been decided by experiment, that a fifth of the breaking-weight will cause deflection, increasing with time, and ultimately producing a permanent set. By an examination of the table, it will be discovered that wood of old trees is much weaker than that of those of mean age; also that timber is stronger as it is heavier, though the increase in all examples is not exactly proportionate to its solidity.